Aerospace & Defense Technology - December 2023 - 10

Composites
σ × ε
σ × T
16.86
15.16
σ
ε
13.46
11.76
10.06
8.36
6.66
4.96
3.26
1.56
-0.14
-0.151
75
3.301
5.027
6.753
8.479
Strain (%)
A chart showing elastic limit or the greatest amount of stress the material can have without taking a
permanent set.
σ × ε
16.68
15.02
13.35
11.69
10.02
8.35
6.69
5.02
3.35
1.69
0.02
0.005
σ × T
ε × T
10.205
11.931
13.657
15.383
17.109
Ys
9.46
ε
σ
MOE
Pt
Pt2
8.34
1.462
537.88
max
@max
16.68
8.317
ε × T
industry standards and, as a result, are less
likely to have manufacturing errors.
Material Testing Composites
Composites are made by combining
two or more materials - often materials
with very different properties. Material
testing is another type of force measurement
which can be very helpful for testing
composites. The only difference is that
the sample's dimension is used to determine
results. For example, a load result
is called stress in material testing. Stress
is the load result divided by the sample's
cross-sectional area. This is why stress has
the unit pounds per square inch using
imperial measurement. Using SI units,
the common unit for stress is Newton per
millimeter squared (N/mm2). N/mm2 is
a MegaPascal (MPa). Stress = Force/Area.
Strain is distance from force measurement.
Strain is a unitless value, but is
often shown as a percentage and referred
to as % Elongation. Like stress, strain uses
the dimensions of the sample, in this case,
the sample length (or Gage Length). If the
sample had an original length of 1 inch
(25 mm) and then was pulled to 2 inches
(50mm), the strain is equal to 100 percent.
Strain equals Ultimate Gage Length
minus the Original Gage Length divided
by the Original Gage Length ([L1-L0]/L0).
Predominately, it is the advancements
MOE
537.88
1.6973.389
5.081
6.773
8.46510.157
Strain (%)
A chart showing elastic modulus. The modulus of elasticity represents the stiffness of the material under
test. In tensile applications, this modulus is often called Young's Modulus and is the relationship between
stress and strain within the proportional limit.
By exporting measurement data
through USB or wirelessly across Bluetooth,
manufacturers can access data
and insight far beyond the basic figures
provided by other force measurement
approaches. Inputting the requirements
of a part, material or component allows
the software to generate high-resolution
graphs based on load, distance, height
and time of measurement. In addition,
in the case of the Starrett L2 Plus and L3
systems, historical test data is archived
10
and available to analysis at a future date,
helping speed up further tests and navigating
potential problems or errors.
This intelligent software increases the
accuracy of force measurement, while
also improving precision for engineers
designing and creating components. By
gaining complete control with a system
like this, design engineers are less restricted
and can be more innovative with their
designs. In addition, quality control managers
can be confident that parts will meet
mobilityengineeringtech.com
11.850
13.542
15.234
16.926
in polymer composites that are changing
the way composites are used. Composites
based on polymer continue to
evolve and find their way into all kinds
of products for aerospace, medical and
automotive applications. Polymer composites
have a high strength to weight
ratio and are relatively easy and inexpensive
to manufacture.
Product designers and OEMs want
to ensure their polymer composite can
withstand the force that will be placed
on it. They also need to know if the
material will stretch or elongate and pinpoint
its exact breaking point. The major
objective of any test and measurement
process is to build a coherent set of materials
data, but in the case of composite
materials, one size rarely fits all.
Software Solutions for Composite
Testing
The diversity of composites presents
difficulties when establishing a coherent
Aerospace & Defense Technology, December 2023
Stress (Mpa)
Stress (Mpa)

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Aerospace & Defense Technology - December 2023

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